Material-architecture-manufacture integrated strategy for piezoelectric metamaterials with mechanical protection and self-powered sensing

The increasingly complex tasks of intelligent equipment have shifted the demand for structural materials from mere lightweight protection to multifunction integration, i.e., high recoverable energy absorption and accurate monitoring. Herein, we presented a material-architecture-manufacture integrated strategy for piezoelectric metamaterials to simultaneously achieve mechanical protection and self-powered sensing. Specifically, an intercalation heterostructure of silane-modified barium titanate (K-BTO)/MXene was constructed to improve the interfacial polarization effect, and an innovative electric field–assisted 4D printing technology could effectively induce the in situ poling of K-BTO. Furthermore, the Kagome lattice–inspired metamaterial (k-CAH) exhibited superior specific energy absorption (0.18 joules per gram), resulting from compression-bend-torsion coordination and multidirection coupling mechanisms. The multimode coupling deformation and local strain amplification mechanism, induced by the geometry design, substantially improved output capacities through activating various piezoelectric response modes at low frequency. With the material-architecture-manufacture synergy, g 33 eff reached up to 1.712 volt-meters per newton. The developed piezoelectric metamaterial system exhibited accurate self-powered sensing of real-time impact and high-efficiency energy harvesting under microvibration conditions, promising for the next-generation smart structural materials.